Electric impulse counter



Oct. 24, 1950 E MlLLEN 2,527,023

ELECTRIC IMPULSE COUNTER Original Filed May 11, 1944 3 Sheets-Sheet lINVENTOR. 0WIN R. mILLtI/V.

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3 Sheets-Sheet 2 INVENTOR. 0 WIN 2. mILLEN Oct. 24, 1950 E. R. MILL EN2,527,023

ELECTRIC IMPULSE COUNTER Original Filed May 11, 1944 3 Sheets-Sheet 3Patented Oct. 24, 1950 UNITED STATES PATENT OFFICE ELECTRIC IMPULSECOUNTER Edwin R. Millen, McCandless Township, Allegheny County, Pa.,assignor to Fisher Scientific Company, Pittsburgh, Pa., a

7 Pennsylvania.

corporation of I Original application May 11,1944, Serial. No.

535,156. Divided and this application June 26, 1946, Serial No. 679,531

vices essentially comprise a relay or solenoid actuated by the pulsatingcurrent to be measured and an escapement or other mechanism operativelyconnected to the counter arm. Such de vices present serious deficiencieswhich, at least to a large extent, the present invention overcomes.Among'these is the fact that in a high speed mechanical escapement, alarge number of light parts are required to translate the linear motionof the relay to the rotary motion of the counter arm with the resultthat the small surfaces of these partswear rapidly and soon causeinaccuracies in the counting. Also, the large number of mechanical partsmay result in a lagging of the counting indication behind the energyimpulses and this lag produces inaccuracies, particularly when countinghigh speed inputs, or when taking a random count of impulses which mightvary instantaneously from a pulse rate of 3 claims. (Cl. 235 92) one persecond to one of fifty per second. Further, the lightness of thematerial required for high speed operation limits the travel of thecounter arm to small magnitudes, thereby limiting the load that thecounting devices can carry. and necessitating the use of small counterscales which are diflicult to read. Another disadvantage also related tothe mechanical escapement is that certain signals, due to their Waveshape voccasionally fail to activate the relay of the device. 3

Accordingly, it is an object of this invention to provide an impulsecounting device that is of simple and rugged construction, effectsimmediate translation of each input impulse into properly indexed rotarymotion, responds promptly and accurately to widely varying impulserates,

affords adequate power to permit wear resisting construction and theoperation of easily read scale means, and avoids or reduces theaforementioned disadvantages.

Other objects will appear hereinafter.

In accordance with this inventioma counting device for measuringpulsating energy is provided which comprises a motor having at least twoelectrically opposed pole pieces or electromag netsdisposed intheisameplane and a specially formedfrotondescribed more in detailhereinafter, mountedin the plane of the pole pieces. Preferably,geometrically opposed pairs ofpole pieces areprovidedthe'pairs of whichare energized and de-energized successively by an electronicswitchorftriggerfcircuit, suchas a form of the familiar Eccles-Jordan ,triggercircuit, which connects opposed pairs of the pole pieces successively tothe source of, energy.

The rotor provided by the invention has an even number of uniformly.spaced and diametrically opposed armfs' each of which is provided at itsendwith'a shoulder which projects laterally in the directionflofrotation of the rotor and which progressively decreases in crosssectional area in that direction, Pulse counting mechanism is operatedby the rotor for recording the counts represented by the individualmovements of the rotor,v e. g., a finger that moves over a calibrateddial or a calibrated dial that is moved energization permits the arms tomove to the energized poles and be locked there. The next impulsereverses'this action by energizing the next succeeding pair of polepieces and de-energizing the previously energized pair. The shaping ofthe arms results inpa rotation in one direction only, i. e., in thedirection toward which the progressively decreasing shoulder projects.Thus, the rotor and the counter means actuated by it are rotatablyindexed by each succeeding impulse in one direction, and an accuratecount of impulses is conveniently achieved.

Referring now to the drawings, Fig. 1 is a perspective, exploded frontview of one form of motor provided by the invention, with associatedoperating mechanism, certain portions being cut away to show underlyingparts; Fig. 2 is a section taken along the vertical diameter of anassembled electric switch; and Fig. 4 is a front elevationof onepermissible alternate form of the rotor.

In the preferred embodiment shown by the g drawings,gamstandard lsupports a housing 2,

18 will be rotated by the rotor H. rotation is, in turn, produced byenergy impulses feeding through a trigger circuit 3|, Fig. 3, to

A rotor H is mounted on a shaft 12 and it is provided with six arms l4extendingradia-lly from the shaft and spaced at 60 intervals thereabout.The rotor is mounted with the arms l4; disposed in the plane of thestator pole pieces and extending substantially to their faces. The endsof the arms are specially formed, in a manner to be described, so as torotate only in a" Rotor shaft [2 has its rear clockwise fashion. endrotatably mounted in a bearing formed in 4 will fire initially, when thebattery or anode supply voltage is first applied, this being due tominute variations in the tubes such as element spacing, gas pressure,heater temperature, activity, etc. It also should be noted that theparticular circuit shown includes means such as a common cathoderesistor for automatically adjusting hold-off bias and evening outvariations in battery supply voltage, as well as a pair of condenserswhich cause a gradual dissipation of coil energy and produce smootherrotor rotation. These elements will be readily understood by thoseacquainted with these circuits. However, since it also will be evidentto such persons that rte-arrangements of this particular circuit canproduce the same effect, it should be understood the housing (Fig. 2)and the other end is rigidly I attached to a shaft l8 carrying a pinionH. An

indicator disc, or drum, is is geared to the motor shaft through a geartrain consisting of pinion I1, gear (9, pinion 28, and gear 2|, Fig. 1.Gear 2| is keyed on a stub shaft 22 which extends through drum i8 and islocked thereto by a nut 23 so that the drum will rotate with it. Pinionis mounted on a shaft 24, and both shafts, 22 and 24 are rotatablymounted in a disc 26 which functions as a bearing for these shafts.

From the above, it is apparent that the drum The rotors successivelyenergize and de-energize the pairs of pole pieces of the motor. Theswitching effect of the trigger circuit is achieved through the use ofthyratron tubes 32 and 33, such as R. C. A. 2050 or 2051. Tube 32 iselectrically connected to the pair of magnets 4 and 5, and tube 33 isconnected in the same manner to the pair 6 and I. A battery 36 suppliesthe power for the circuit and the motor, or, if desired, an A. C. powersupply with conventional rectifier and filter arrangement may besubstituted.

When it is desired to make a count of the energy impulses in anyelectric circuit, terminals 31 and 38 of the trigger circuit areconnected to the output of the circuit to be tested. When the firstimpulse is received from that circuit, tube 32 is rendered conductiveand the current flows to energize pole pieces 4 and 5 and the rotor armsdisposed at 150-330 (Fig. 1) are magnetically attracted to the faces ofthese pole pieces. The next impulse, regardless of wave shape, renderstube 32 non-conductive and tube 33 conductive so that pole pieces 4 and5 are deenergized and release their'hold on the rotor arms, while pieces5 and I are energized and magnetically attract to their faces the rotorarms then disposed at 60-240 (Fig. 1). Each successive impulse energizesand de-energizes .the pairs of pole pieces in the manner just describedto rotatably index the rotor, as well as drum 18. The periphery of drumI8 is calibrated so that each impulse will advance it one mark. An indexfinger 39 is mounted as shown and indicates the total impulses.

The switching action of the trigger circuit is due to the fact that thetubes are so connected together that the firing of one establishes anegative grid bias in the other which prevents the other from firing.With such a condition pertaining a subsequent positive input pulseslightly larger in amplitude than the established bias will then firethe second tubeand extinguish the tube formerly conducting. Also, onlyone tube that the invention is not limited to this particular circuit.

It is preferable for some purposes to provide means for automaticallyshutting off the power supply of the motor after 'agpredetermined numberof counts. This can be done in various ways as by mounting cam membersat appropriate points on the face of drum l8 to operate switches in thepower circuit, or in other ways/that will appear to those skilled in theart.

It is important to this invention that rotor arms is be formed in such away that they rotate in one direction only. Accordingly, each arm isprovided with a shoulder portion 4! that pro-- gressively decreases incross sectional area in the direction of the, rotation, most suitably toa relatively sharp nose as shown. In this way the mag netic reluctanceof the rotor decreases in the desired direction of rotation andincreasesin the other direction. The result is that, as seen from Fig.1, when two aligned arms are aligned with a pair of magnets, the nextadjacent pair of aligned arms in the direction of rotation lie withtheir noses closely adjacent to the pair of magnets which will beenergized next. Thus, when thyratron tube 32 fires, the rotor is causedto move in a clockwise direction, there being little tendency for it torotate counter-clockwise. It is noted that the magnetsnot only pull thearms to them, but also lock these arms magnetically in position aftereach impulse. This locking action is normally sufficient to prevent;mechanical chattering or vibration. However, for high speed action, aratchet or no-back mechanism (not shown) may be added to help mechanicaldamping.

Other forms of rotors are possible provided they are so shaped as tohave increased reluctance in one direction of rotation and decreasedreluctance in the other. Such an alternate form is shown in Fig. 4 andhas the shoulders 55 which are decreasingly tapered in acounter-clockwise direction to produce rotation in that direction. Thisrotor completesone 360 revolution with every 20 input pulses while thatshown in Fig. 1 makes a complete revolution with 12 input pulses.Another form of rotor (not shown) which could be used, would havesuccessive lengths of its periphery crimped in a saw-tooth fashion so asto provide the rotor with decreased magnetic reluctance in the desireddirection of rotation.

Although this invention has been described with reference togeometrically opposed pairs of pole pieces, it should not be limitedthereto. As will be readily apparent to those skilled in this one of thepole pieces during two successive en ergy impulses becomes firstelectrically opposed to one of its adjacent pole pieces and nextelectrically opposed to the other adjacent one so as to rotatably indexthe rotor in the manner previously described. Subsequent impulses thencause other pole pieces to form electrically opposed pairs with theiradjacent poles to carry on the revolution of the rotor.

The various uses to which this invention can be put will be apparent tothose in the else-- tronic art. It is particularly useful for randomcounting or counting the impulses in high frequency currents, and byreason of the fact that it provides a high ratio of conversion ofelectrical energy into mechanical torque, the motors can be made notonly to operate power switches but also as powerful as need be for thepurposes to Which these impulse actuated devices are put. Further, thecircuit shown is sensitive todirections or polarity of the input pulsesso that, if an alternating current voltage is applied to the A input,the counter will indicate one count for each cycle. By known methods, itis possible to make the switch sensitive to impulses of either positiveor negative at will.

According to the provisions of the patent statutes, I have explained theprinciple and mode of operation of my invention and have illustrated anddescribed what I now consider to represent its best embodiment. However,I desire to have it understood that, within the scope of the a'ppendedclaims, the invention may be practiced otherwise than as specificallyillustrated and described.

I claim:

1. Apparatus for counting pulses of electrical energy of varying waveshapes and durations comprising opposed pairs of pole pieces disposed inthe same plane, a rotor mounted within the plane of said pole pieces andhaving successive lengths of its periphery shaped to provide decreasingmagnetic reluctance in the desired direction of rotation, counting meansoperatively connected to said rotor, ,a source of electrical power forenergizing said pole pieces, a circuit operatively connecting said polepieces with said source and adapted to successively energize anddeenergize the pairs of opposed poles, said circuit including anelectronic switch electrically connected to the source of saidelectrical pulses,

said switch including at least a pair of thyratron tubes operativelyconnected together to alternately transfer in response to said impulsessaid power to successively energize and deenergize the pairs of polepieces.

2. Apparatus for counting pulses of electrical energy of varying waveshapes and durations comprising opposed pairs of pole pieces disposed inthe same plane, a rotor mounted within the plane of said pole pieces,said rotor having an even number of uniformly spaced arms each providedat its end with a shoulder projecting laterally in the desired directionof rotor rotation and progressively decreasing in cross sectional areain that direction, counting means operatively connected to said rotor, asource of electrical power for energizing said pole pieces, a circuitoperatively connecting said pole pieces with said source and adapted tosuccessively en-- ergize and deenergize the pairs of opposed poles, saidcircuit including an electronic switch e1ectrically connected to thesource of said electrical pulses, said switch including at least a pairof thyratron tubes operatively connected together to alternatelytransfer in response to said impulses said power to successivelyenergize and deenergize the pairs of pole pieces.

3. Apparatus for counting pulses of electrical energy of varying waveshapes and durations comprising two pairs of opposed pole piecesdisposed at right angles in the same plane, a rotor mounted within theplane of said pole pieces, said rotor having an even number of uniformlyspaced arms each provided at its end with a shoulder projectinglaterally in the desired direction of rotor rotation and progressivelydecreasing in cross sectional area in that direction, counting meansoperatively connected to said rotor, a source of electrical power forenergizing said pole pieces, a circuit operatively connecting said polepieces with said source and adapted to successively energize anddeenergize the pairs of opposed poles, said circuit including anelectronic switch electrically connected to the source of saidelectrical pulses, said switch including at least a pair of thyratrontubes operatively connected together to alternately transfer in responseto said impulses said power to successively energize and deenergize thepairs of pole pieces.

EDWIN R. MILLEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 362,322 Sheehy May 3, 1887491,970 Meston Feb. 14, 1893 1,258,497 Straub Mar. 5, 1918 1,371,096Howe and Warner Mar. 8, 1921 1,638,973 Walker Aug. 16, 1927 1,933,086Battegay Oct. 31, 1933 2,156,969 Bryce May 2, 1939 2,249,029 MullerheimJuly 15, 1941 2,428,882 Kolff Oct. 14, 1947 FOREIGN PATENTS NumberCountry Date 401,987 Great Britain Nov. 23, 1933 522,557 Great BritainJune 20, 1940

